For robust time delay estimation, we propose a new subspace-based algorithm which estimates the phase shift not between the adjacent samples of the dechirped sinusoid but between the dechirped sinusoids in different bands. We analyze the proposed and the conventional method in AWGN channel and verifiy the proposed algorithm through Monte-carlo simulations in AWGN and multi-path channels.

In this letter, we present a novel timing offset estimation method for chirp-based communication systems which is robust against frequency offset. For robust timing offset estimation, we propose a partial cross-correlation and differential multiplication method using up and down chirp symbols. The performances of the proposed estimator in indoor multipath channel model provided by IEEE 802.15.4a standard are presented in terms of mean-square error (MSE) obtained by computer simulation. The simulation results show that the proposed estimator has a significantly smaller MSE than the conventional estimators.